5.3 The radial potentials

The potentials which enter into the coupled equations are given by Eq. (5.9). For simple two-body potentials inserted between the scalar harmonics of Simonov, the corresponding integral can be carried out analytically [5354]. Otherwise, the computation is more painful. A possible strategy consists of expanding the potential itself into HH, say

           ∑
V (ξ,Ω5 ) =     v[L](ξ)Q[L](Ω5 ),
            [L]
(5.17)

where the summation is restricted to HH that are scalar and fully symmetric, i.e., of the type Q[L] = VL3ν. Then

             ∑
V [L],[L]′(ξ) =    v[L]′′(ξ) ⟨[L ]′ | [L ]′′ | [L]⟩ .
             [L]′′
(5.18)

The so-called

3H coefficients which enter into the above expression are independent of the potential and thus can be stored once aand for all. They are given by

                  ∫
⟨[L ]′ | [L]′′ | [L ]⟩ = dΩ5P ∗[L](Ω5 )Q[L]′′(Ω5 )P[L]′(Ω5) ,
(5.19)

and are submitted to the selection rule |L L′|≤ L′′L + L.